30 research outputs found
Homeowner pest management: a guide for garden center sales personnel
1 online resource (PDF, 20 pages)Includes Understanding pesticide toxicity, AGFS 3947 (1990)This archival publication may not reflect current scientific knowledge or recommendations. Current information available from the University of Minnesota Extension: https://www.extension.umn.edu
Accounting for Impact? The Journal Impact Factor and the Making of Biomedical Research in the Netherlands
The range and types of performance metrics has recently proliferated in academic settings, with bibliometric indicators being particularly visible examples. One field that has traditionally been hospitable towards such indicators is biomedicine. Here the relative merits of bibliometrics are widely discussed, with debates often portraying them as heroes or villains. Despite a plethora of controversies, one of the most widely used indicators in this field is said to be the Journal Impact Factor (JIF). In this article we argue that much of the current debates around researchers’ uses of the JIF in biomedicine can be classed as ‘folk theories’: explanatory accounts told among a community that seldom (if ever) get systematically checked. Such accounts rarely disclose how knowledge production itself becomes more-or-less consolidated around the JIF. Using ethnographic materials from different research sites in Dutch University Medical Centers, this article sheds new empirical and theoretical light on how performance metrics variously shape biomedical research on the ‘shop floor.’ Our detailed analysis underscores a need for further research into the constitutive effects of evaluative metrics
Cancer Biomarker Discovery: The Entropic Hallmark
Background: It is a commonly accepted belief that cancer cells modify their transcriptional state during the progression of the disease. We propose that the progression of cancer cells towards malignant phenotypes can be efficiently tracked using high-throughput technologies that follow the gradual changes observed in the gene expression profiles by employing Shannon's mathematical theory of communication. Methods based on Information Theory can then quantify the divergence of cancer cells' transcriptional profiles from those of normally appearing cells of the originating tissues. The relevance of the proposed methods can be evaluated using microarray datasets available in the public domain but the method is in principle applicable to other high-throughput methods. Methodology/Principal Findings: Using melanoma and prostate cancer datasets we illustrate how it is possible to employ Shannon Entropy and the Jensen-Shannon divergence to trace the transcriptional changes progression of the disease. We establish how the variations of these two measures correlate with established biomarkers of cancer progression. The Information Theory measures allow us to identify novel biomarkers for both progressive and relatively more sudden transcriptional changes leading to malignant phenotypes. At the same time, the methodology was able to validate a large number of genes and processes that seem to be implicated in the progression of melanoma and prostate cancer. Conclusions/Significance: We thus present a quantitative guiding rule, a new unifying hallmark of cancer: the cancer cell's transcriptome changes lead to measurable observed transitions of Normalized Shannon Entropy values (as measured by high-throughput technologies). At the same time, tumor cells increment their divergence from the normal tissue profile increasing their disorder via creation of states that we might not directly measure. This unifying hallmark allows, via the the Jensen-Shannon divergence, to identify the arrow of time of the processes from the gene expression profiles, and helps to map the phenotypical and molecular hallmarks of specific cancer subtypes. The deep mathematical basis of the approach allows us to suggest that this principle is, hopefully, of general applicability for other diseases
Dihydroflavonol Reductase Activity in Relation to Differential Anthocyanin Accumulation in Juvenile and Mature Phase Hedera helix
Flowering in Bougainvillea: A Function of Assimilate Supply and Nutrient Diversion
Reproductive development, whether expressed as first node to flower or numbers of inflorescences developing, is promoted in direct relationship to leaf area and in inverse relationship to the numbers of axillary branches developing. Per cent soluble solids in the reproductive shoots vary with reproductive development. Cytokinin treatments promote inflorescence development and per cent soluble solids, further supporting a nutritional hypothesis in the control of flowering in Bougainvillea “San Diego Red.” Gibberellin treatments inhibit reproductive development completely without significant lowering of per cent soluble solids, which is counter to expectations for a nutritional hypothesis. A closer examination of the reproductive axes, the tissues in which morphogenetic change occurs, must be made for the gibberellin-treated tissues